• Title/Summary/Keyword: ocean environmental

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A Review on the Building Wind Impact through On-site Monitoring in Haeundae Marine City: 2021 12th Typhoon OMAIS Case Study

  • Kim, Jongyeong;Kang, Byeonggug;Kwon, Yongju;Lee, Seungbi;Kwon, Soonchul
    • Journal of Ocean Engineering and Technology
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    • v.35 no.6
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    • pp.414-425
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    • 2021
  • Overcrowding of high-rise buildings in urban zones change the airflow pattern in the surrounding areas. This causes building wind, which adversely affects the wind environment. Building wind can generate more serious social damage under extreme weather conditions such as typhoons. In this study, to analyze the wind speed and wind speed ratio quantitatively, we installed five anemometers in Haeundae, where high-rise buildings are dense, and conducted on-site monitoring in the event of typhoon OMAIS to determine the characteristics of wind over skyscraper towers surround the other buildings. At point M-2, where the strongest wind speed was measured, the maximum average wind speed in 1 min was observed to be 28.99 m/s, which was 1.7 times stronger than that at the ocean observatory, of 17.0 m/s, at the same time. Furthermore, when the wind speed at the ocean observatory was 8.2 m/s, a strong wind speed of 24 m/s was blowing at point M-2, and the wind speed ratio compared to that at the ocean observatory was 2.92. It is judged that winds 2-3 times stronger than those at the surrounding areas can be induced under certain conditions due to the building wind effect. To verify the degree of wind speed, we introduced the Beaufort wind scale. The Beaufort numbers of wind speed data for the ocean observatory were mostly distributed from 2 to 6, and the maximum value was 8; however, for the observation point, values from 9 to 11 were observed. Through this study, it was possible to determine the characteristics of the wind environment in the area around high-rise buildings due to the building wind effect.

Case Study on the Effluent Guidelines of Foreign Cases for the Development of Hazardous Noxious Substances (HNS) from Marine Industrial Facilities Management Guidelines, Korea: Focusing on the US EPA Guidelines (국내 해양산업시설의 위험유해물질 배출 관리 지침개발을 위한 국외 사례 검토: US EPA 배출지침을 중심으로)

  • Ki-young Choi;Chang-joon Kim;Young-Il Kim;Won-Soo Kang;Moonjin Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.spc
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    • pp.44-49
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    • 2022
  • It is necessary to establish a marine environment management system in Korea for hazardous noxious substances (HNS) effluent from marine industrial facilities because the Marine Environment Management Act primarily focuses on pollution control from vessels and offshore man-made structures. In this study, we investigated the effluent guidelines of foreign cases focusing on the US Environmental Protection Agency (US EPA), which provides detailed information on the action levels and establishing principles for the industrial wastewater discharge of HNS. Based on the review, we also considered appropriate options for establishing new guidelines for Korea.

Development and Assessment of LSTM Model for Correcting Underestimation of Water Temperature in Korean Marine Heatwave Prediction System (한반도 고수온 예측 시스템의 수온 과소모의 보정을 위한 LSTM 모델 구축 및 예측성 평가)

  • NA KYOUNG IM;HYUNKEUN JIN;GYUNDO PAK;YOUNG-GYU PARK;KYEONG OK KIM;YONGHAN CHOI;YOUNG HO KIM
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.29 no.2
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    • pp.101-115
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    • 2024
  • The ocean heatwave is emerging as a major issue due to global warming, posing a direct threat to marine ecosystems and humanity through decreased food resources and reduced carbon absorption capacity of the oceans. Consequently, the prediction of ocean heatwaves in the vicinity of the Korean Peninsula is becoming increasingly important for marine environmental monitoring and management. In this study, an LSTM model was developed to improve the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system of the Korean Peninsula Ocean Prediction System. Based on the results of ocean heatwave predictions for the Korean Peninsula conducted in 2023, as well as those generated by the LSTM model, the performance of heatwave predictions in the East Sea, Yellow Sea, and South Sea areas surrounding the Korean Peninsula was evaluated. The LSTM model developed in this study significantly improved the prediction performance of sea surface temperatures during periods of temperature increase in all three regions. However, its effectiveness in improving prediction performance during periods of temperature decrease or before temperature rise initiation was limited. This demonstrates the potential of the LSTM model to address the underestimated prediction of ocean heatwaves caused by the coarse vertical grid system during periods of enhanced stratification. It is anticipated that the utility of data-driven artificial intelligence models will expand in the future to improve the prediction performance of dynamical models or even replace them.

Ocean Current Power Farm Interaction Study (해양 조류발전단지 간섭 연구)

  • Jo, Chul-Hee;Yim, Jin-Young;Chae, Kwang-Su;Park, Ro-Sik
    • Journal of Ocean Engineering and Technology
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    • v.23 no.1
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    • pp.109-113
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    • 2009
  • Several tidal current power plants are being planned and constructed in Korea utilizing the strong tidal currents along the west and south coasts. A tidal current reaches 9.7 m on the west coast; there are few potential regions for tidal current power generation. The construction of a dam to store water can prevent the circulation of water, causing a great environmental impact on the coast and estuary. The tidal barrage could produce a large amount of power, but it should be carefully considered. The purpose of developing renewable energies is to minimize the environmental impact and to maximize the utilization of clean energy. To produce a great quantity of power, tidal current farms require the placement of numerous units in the ocean. The power generation is very dependent on the size of the rotor and the incoming flow velocity. Also, the interactions between devices contribute greatly to the production of power. The efficiency of a power farm is estimated to determine the production rate. This paper introduces 3 D interaction problems between rotating rotors, considering the axial, transverse, and diagonal distances between horizontal axis tidal current devices.

Oil Spill Spreading of Continuous Spills

  • Lee, Jung-Lyul;Chu, Jin-Kyu
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.40-44
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    • 1998
  • Since oil spills discharged by offshore oil production platforms, ship accidents etc., cause many environmental problems, forecasts of drift and spreading of the spilled oil are requested as a basis for oil spill combat management. The numerical approach has been thought as the most effective methods of such forecast. In general, the oil spill model takes into account the trajectory and fate of oil, including drifting, spreading, evaporation, dispersion, emulsification, shoreline standing, and so on. (omitted)

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